Which of the following pairs of equations describes the supply and demand curves given in the accompanying demand and supply tables? $$\begin{array} { | c | c | c | }
\hline \text { Price } & \text { Quantity Supplied } & \text { Quantity Demanded } \
\hline \$ 20 & 0 & 40 \
\hline \$ 25 & 10 & 40 \
\hline \$ 30 & 20 & 40 \
\hline \$ 35 & 30 & 40 \
\hline \$ 40 & 40 & 40 \
\hline \$ 45 & 50 & 40 \
\hline
\end{array}$$
A)Qs = P - 40; Qd = 40P, respectively
B)Qs = P - 20; Qd = 40, respectively
C)Qs = 2P - 40; Qd = 40, respectively
D)cannot be determined

Question

Which of the following pairs of equations describes the supply and demand curves given in the accompanying demand and supply tables? $$\begin{array} { | c | c | c | } 
\hline \text { Price } & \text { Quantity Supplied } & \text { Quantity Demanded } \
\hline \$ 20 & 0 & 40 \
\hline \$ 25 & 10 & 40 \
\hline \$ 30 & 20 & 40 \
\hline \$ 35 & 30 & 40 \
\hline \$ 40 & 40 & 40 \
\hline \$ 45 & 50 & 40 \
\hline
\end{array}$$
A)Qs = P - 40; Qd = 40P, respectively
B)Qs = P - 20; Qd = 40, respectively
C)Qs = 2P - 40; Qd = 40, respectively
D)cannot be determined

Quizplus · Accepted Answer

The supply equation Qs = 2P - 40 fits the pattern where quantity supplied increases by 10 for every $5 increase in price. The demand equation Qd = 40 is constant, matching the table where quantity demanded is always 40.

Which of the Following Pairs of Equations Describes the Supply